Figure 1

(a) Permittivity distribution of the original Luneburg lens, as defined by Eq. 1. (b) 2D numerical simulation of beam propagation in the device, with two different input beams entering through the top (curved) edge from two different angles produce a focused output beams that is normal to the flat (lower) surface. (c) Permittivity distribution of the transformed Luneburg lens. (d) Photo of one of the fabricated Luneburg lenses with silver coated on both top and bottom, with radiation shields removed.